This application relates to a unique block construction for forming toy blocks which can be either interconnected to form a train, or stacked on top of each other. A block according to the invention includes a coupling which has a retracted position in which it forms part of the basic block contour when the block is to be stacked, and which can be manipulated into a protracted position for coupling the block to another block to form a train.
According to the invention, the block has a bottom portion with wheels which roll in order to move the block. The block has a top portion which can support the bottom portion of another block of similar construction and minimize relative lateral shifting of the blocks, to allow stacking of the blocks. The block has a coupling member which can move between a retracted position and a protracted position. When it is in a retracted position, the coupling member forms a part of the basic contour of the block, so that the block has a true block contour when it is to be stacked. When the coupling member is in a protracted position, it projects partly from the block for coupling the block with another block to form a train.
Preferably, the coupling member is slidable in a slot formed in the block. When the coupling member is in its retracted position, it is disposed completely in the slot. When the coupling member is moved to its protracted position, it projects out of one part of the slot and creates a recess in another part of the slot. The slot has notches adjacent its ends, and the coupling member carries locking tabs which can engage the notches. Thus, when a coupling member projecting from one block slides into a recess formed in another block, the locking tab on the projecting coupling member engages the notch in the recess, thereby coupling the blocks together to form a train.
The top side of the block can engage the bottom side of another block of similar construction and minimize relative lateral movement between the blocks, to thereby allow stacking of the blocks. The top side of the block has arcuate recesses for receiving the wheels on the bottom side of another block in a way which resists rolling movement of the wheels. The top side of the block is also designed to block sideways shifting of the wheels. Thus, a pair of blocks can be stacked in such a manner that the blocks cannot roll, or shift sideways relative to one another.
Significantly, the configuration of the coupling member and the slot allows the block to have a true block contour (i.e., no protruding parts) when it is stacked on another block. The ends of the coupling member have flat surfaces which, when the coupling member is disposed completely in the slot, are generally aligned with the side walls of the block, and form part of the basic contour of the block.